Effects of essential oil and phenolic extracted from clove leaves (Syringa portolaciniata) on postharvest apple pathogens and quality

The bioactivities of phenolic and essential oil extracted from clove leaves(Syringa portolaciniata) in vivo and vitro against Penicillium expansum, Botrytis cinerea, Colletotrichum gloeosporioides, Macrophoma kawatsuka, Monilia fructigena and Trichothecium roseum, and their effects on the quality of postharvest apple fruits were studied. Results show that phenolic and essential oils demonstrate inhibitory activities in vitro against the six microorganisms with 0.15～0.35 mg/(100 mL) and 0.15～0.30 mg/(100 mL) values of MIC(minimum inhibitory concentration), respectively. But essential oils and phenolic can not compeletly inhibit pathogen growing in the apples. With the treatment of phenolic and essential oil, the rate of rotted fruits, respiration rate and brown index of apple fruits decrease. Firmness, soluble solid content(SSC) and titrable acid(TA) of the apple are maintoined, which retard physiological senescence of the fruits. Adding CaCl₂ can improve the efficiency of phenolic and essential oil, which will be developed into potential preservative for fruit storage.